I have been trying to have a baby for 5 years now, so the obgyn put me on metformin. I have been on them since November 500mg.my last period was dec.24,2011.I'm 8 weeks late the hpt test says negative which I took in January... what should I do? Could I be pregnant

If your periods had been regular until now, I would check with the doctor about having a blood test done. What fertility testing have you already had done?